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排序方式: 共有407条查询结果,搜索用时 15 毫秒
71.
Ho D Fitzgerald M Bartlett CA Zdyrko B Luzinov IA Dunlop SA Swaminathan Iyer K 《Nanoscale》2011,3(3):907-910
RADA16 self-assembling peptide nanofiber scaffolds (SAPNSs) have been shown to have positive effects on neural regeneration following injury to the central nervous system in vivo, but mechanisms are unclear. Here we show that RADA16 SAPNSs form scaffolds of increasing fiber density with increasing peptide concentration which in turn has a concentration-dependent effect on neurons and astrocytes in mixed retinal cultures. Importantly, we report that the final nanoscale fiber architecture is an important factor to consider in designing scaffolds to promote regeneration in the central nervous system. 相似文献
72.
S. Kalaiselvam M. S. Gugan E. Kuraloviyan R. Meganathan A. Niruthiya Priyan M. R. Swaminathan 《热科学学报(英文版)》2009,18(4):358-363
This paper analyzes the effects of nanoporous surface on heat transfer temperaments of assorted thermal conducting materials.
A phenomenal proposal of wielding the surface roughness to ameliorate the heat transfer rate has been discovered. The maximum
increase of heat transfer rate procured by nanoporous layers is 133.3% higher than the polished bare metals of surface roughness
0.2 μm. This plays an imperative role in designing compact refrigeration systems, chemical and thermal power plants. Experimental
results picture a formidable upswing of 58.3% heat transfer in chemically etched metals of surface roughness 3 μm, 133.3%
in nanoporous surface of porosity 75–95 nm formed by electrochemical anodization, and porosity of 40–50 nm formed by spray
pyrolysis increases the heat transfer by 130%. Effects of porosity, flow velocity and scaling on the energy transfer are also
scrutinized. This paper also analyzes the multifarious modes of nanoporous fabrication, to contrive both prodigious and provident
system. 相似文献
73.
Mallikarjuna Shroff Rama Ramesh NeppalliRamesh Chellaswamy Sivaram Swaminathan 《Composites Science and Technology》2010
The efficiency of potassium succinate-g-polypropylene (KPPSA) as compatibilizer for the dispersion of clay in a high molecular weight polypropylene during melt mixing for the preparation of nanocomposites was evaluated and compared with maleic anhydride-g-polypropylene (PPMA). Nanocomposites were prepared by direct melt mixing and by masterbatch methods and the structure obtained was characterized by WAXD and TEM. The exfoliation and better dispersion of the organoclay was observed with KPPSA than PPMA. The dispersion of clay was found to be dependent on the method of preparation, type and the amount of compatibilizer used. The dispersion was better when the nanocomposites were prepared by two step masterbatch route than the single step direct mixing method. Flexural moduli and crystallization behavior were studied and correlated with the dispersion of organoclay in the PP matrix. 相似文献
74.
Angayarkanni J Palaniswamy M Murugesan S Swaminathan K 《Journal of Bioscience and Bioengineering》2002,94(4):299-303
The pectinase enzymes isolated from Aspergillus spp., A. indicus, A. flavus and A. niveus were used for fermentation of tea leaves. The enzymes were purified and characterized. The effect of both crude enzyme preparation and purified pectinase enzymes on the improvement of tea leaf fermentation were determined in terms of theaflavin, thearubigin, high polymerized substances, total liquor colour, dry matter content and total soluble solids of the tea produced. The crude enzyme preparations obtained from ethanol precipitation were found to be more effective in improving tea leaf fermentation than the purified pectinase enzymes. 相似文献
75.
PulseNet standardized protocol for subtyping Listeria monocytogenes by macrorestriction and pulsed-field gel electrophoresis 总被引:4,自引:0,他引:4
PulseNet is a national network of pubic health and food regulatory laboratories established in the US to detect clusters of foodborne disease and respond quickly to foodborne outbreak investigations. PulseNet laboratories currently subtype Escherichia coli O157:H7, non-typhoidal Salmonella, and Shigella isolates by a highly standardized 1-day pulsed-field gel electrophoresis (PFGE), and exchange normalized DNA "fingerprint" patterns via the Internet. We describe a standardized molecular subtyping protocol for subtyping Listeria monocytogenes that was recently added to PulseNet. The subtyping can be completed within 30 h from the time a pure culture of the bacteria is obtained. 相似文献
76.
Ali Afrasiabi Nicole L. Fewings Stephen D. Schibeci Jeremy T. Keane David R. Booth Grant P. Parnell Sanjay Swaminathan 《International journal of molecular sciences》2021,22(6)
Although the causes of Multiple Sclerosis (MS) still remain largely unknown, multiple lines of evidence suggest that Epstein–Barr virus (EBV) infection may contribute to the development of MS. Here, we aimed to identify the potential contribution of EBV-encoded and host cellular miRNAs to MS pathogenesis. We identified differentially expressed host miRNAs in EBV infected B cells (LCLs) and putative host/EBV miRNA interactions with MS risk loci. We estimated the genotype effect of MS risk loci on the identified putative miRNA:mRNA interactions in silico. We found that the protective allele of MS risk SNP rs4808760 reduces the expression of hsa-mir-3188-3p. In addition, our analysis suggests that hsa-let-7b-5p may interact with ZC3HAV1 differently in LCLs compared to B cells. In vitro assays indicated that the protective allele of MS risk SNP rs10271373 increases ZC3HAV1 expression in LCLs, but not in B cells. The higher expression for the protective allele in LCLs is consistent with increased IFN response via ZC3HAV1 and so decreased immune evasion by EBV. Taken together, this provides evidence that EBV infection dysregulates the B cell miRNA machinery, including MS risk miRNAs, which may contribute to MS pathogenesis via interaction with MS risk genes either directly or indirectly. 相似文献
77.
Construction of broadband passive macromodels from frequency data for simulation of distributed interconnect networks 总被引:2,自引:0,他引:2
Sung-Hwan Min Swaminathan M. 《Electromagnetic Compatibility, IEEE Transactions on》2004,46(4):544-558
This paper discusses a method for the construction of multiport broadband passive macromodels using frequency data obtained from an electromagnetic simulation or measurements. This data could represent the frequency response of a distributed interconnect system. The macromodels are generated using rational functions by solving an eigenvalue problem. For numerical computation, the macromodels are represented as a summation of rational functions consisting of low-pass, band-pass, high-pass, and all-pass filters. The stability and passivity of the macromodels are enforced through constraints on the poles and residues of rational functions. To enable the construction of broadband macromodels, methods based on band division, selector, subband reordering, subband dilation, and pole replacement have been used. Two test cases that describe the performance of the proposed algorithm, and three test cases that are representative of distributed systems have been analyzed to verify the efficiency of the method. 相似文献
78.
C. L. Reynolds V. Swaminathan M. Geva L. E. Smith L. C. Luther 《Journal of Electronic Materials》1995,24(6):747-750
Unintentional zinc diffusion into uniformly Si-doped InP layers has been studied. The sharp non-error function Zn concentration
profiles and inflections are shown to be consistent with the substitutional-interstitial mechanism when the influence of the
electrostatic field of the pn-junction on diffusion is taken into consideration. 相似文献
79.
Design of integrated low noise amplifiers (LNA) using embedded passives in organic substrates 总被引:1,自引:0,他引:1
The noise figure of a low noise amplifier (LNA) is a function of the quality factor of its inductors. The lack of high-Q inductors in silicon has prevented the development of completely integrated complementary metal oxide semiconductor (CMOS) LNAs for high sensitivity applications like global system for mobile communications (GSM) (1.9 GHz) and wideband code-division multiple-access (W-CDMA) (2.1GHz). Recent developments in the design of high-Q inductors (embedded in low cost integrated circuit (IC) packages) have made single-package integration of RF front-ends feasible. These embedded passives provide a viable alternative to using discrete elements or low-Q on-chip passives, for achieving completely integrated solutions. Compared to on-chip inductors with low Q values and discrete passives with fixed Q/sub s/, the use of these embedded passives also leads to the development of the passive Q as a new variable in circuit design. However, higher Q values also result in new tradeoffs, particularly with respect to device size. This paper presents a novel optimization strategy for the design of completely integrated CMOS LNAs using embedded passives. The tradeoff of higher inductor size for higher Q has been adopted into the LNA design methodology. The paper also presents design issues involved in the use of multiple embedded components in the packaging substrate, particularly with reference to mutual coupling between the passives and reference ground layout. 相似文献
80.
Population-based cancer registries from Algeria, China, Costa Rica, Cuba, India, the Philippines, and Thailand are collaborating with the International Agency for Research on Cancer in a study of cancer survival in developing countries. Comparisons with the SEER program results of the National Cancer Institute in the United States, and the EUROCARE study of survival in European countries revealed considerable differences in the survival of patients with certain tumors associated with intensive chemotherapeutic treatment regimes (Hodgkin's disease and testicular tumors), more modest differences in the survival of patients with tumors for which early diagnosis and treatment confer an improved prognosis (carcinomas of the large bowel, breast, and cervix), and only slight differences for tumors associated with poor prognosis (carcinomas of the stomach, pancreas, and lung). With limited resources to meet the challenge of the increasing incidence of cancer expected in the next few decades, health authorities in developing countries should be aware of the importance of investing in a range of cancer control activities, including primary prevention and early detection programs as well as treatment. 相似文献